From the BBC website:
What did AstraZeneca say?
It said there was no evidence of an increased risk of clotting due to the vaccine.
It said that across the EU and United Kingdom there had been 15 events of deep-vein thrombosis (DVT) - a blood clot in a vein - and 22 events of pulmonary embolism - a blood clot that has entered the lungs - reported among those vaccinated.
AstraZeneca said these figures were "much lower than would be expected to occur naturally in a general population of this size and is similar across other licensed Covid-19 vaccines".
"The nature of the pandemic has led to increased attention in individual cases and we are going beyond the standard practices for safety monitoring of licensed medicines in reporting vaccine events, to ensure public safety," Ann Taylor, the firm's chief medical officer, said.